Hey ya'll not to be a deal pooper but...
<< Dimensions: Rare, non-standard size, 9X9cm (92mm x 92mm, 3 5/8" edge-to-edge distance) for special computer cases such as some older models of In Win. Actual distance between adjacent mounting holes: 3 1/4". Check the size of the case fan mounting mechanism in your computer case before purchase this item. >>
You may be able to use these or maybe not, worst case is your out .99 + S&H.
If they don't fit in your case you can always mod them to be a blowhole and they come with a finger guard.
In reply to BigEdMuustaffa: There are so many schools of thought on fans, # of fans, speed, CFM, postive pressure (in the case), negative pressure, ect. that you need to discover your own methodolgy. The only thing that is true and constant is that filters help keep the case clean, as dust and hair is not conductive to electronics running their best. Good Luck...